1. Field of the Invention
This invention relates to a device for insertion of a plastic pipe section into a shaped plastic piece for welding, in accordance with a heating element method. Two carriages, which have clamping elements, are positioned on a base frame and are displaceable relative to each other with a setting device. A heating device is pivotal into and out of a position between the two clamping elements with the clamped plastic pipe section and the clamped shaped plastic piece with levers pivotally seated on the base frame. The heating device has a heating element with a cupped section for placing over the plastic pipe section and a cylindrical section for insertion into the shaped plastic piece.
2. Description of the Prior Art
A conventional device is known from German Letters Patent DE-PS 27 34 911. When a heating device is pivoted into place, clamping elements with a clamped plastic pipe section and a clamped, shaped plastic piece are positioned in a direction towards a heating element. The cup-shaped section is placed over the plastic pipe section, so that the outside of the plastic pipe section is heated and plasticized. In addition, the cylinder-shaped section is inserted into the inside of the shaped plastic piece, so that the inside wall of the shaped plastic piece is heated and plasticized. Once plastification has progressed sufficiently, the heating device is pivoted away and the clamping elements are displaced towards each other far enough that the plastic pipe section is inserted into the shaped plastic piece. In the process, the heated and plasticized surfaces contact each other and are firmly connected with each other during cooling.
This conventional device is limited to use with a fixed exterior diameter of the plastic pipe section and a fixed interior diameter of the shaped plastic piece which has been adapted to it. However, when laying networks of plastic pipe, the diameter changes so that not only different devices are required but also different heating devices are required.
If the heating device as a whole, together with the levers, is changed, a large amount of time is lost in retooling for the welding work. The same is true if only the heating element of the heating device is exchanged. To do this, the heating element must first cool in order to be exchanged, and the new heating element must be heated before welding can continue. In either conventional case, expensive retooling times must be tolerated.